The present invention relates in general to continuous treatment lines for textile webs and, in particular to a line for irradiation and chemical treatment of the webs, including a web supply station, a station for treating the webs by a liquid, and an irradiation station having a ray accelerator provided with a ray exit window, a washing station, a drying station, take-up means with a web-storing station, and transport means for feeding the web between the stations and cooperating with control means for regulating the advance of the web and for spreading the web on the feeding means. The line is suitable, for instance, for the manufacture of hydrophilic, antistatic or antibacterial webs. The treatment of such webs is effected by means of electron rays, and consequently an effective protection or screening against the electron radiation from such progressive lines is of particular importance.
A continuous processing line for irradiation and chemical treatment of textile webs is known, which consists of a device for supplying a web to be treated from a store, a device for treating the web in liquid, a device for irradiation of the web by means of a ray accelerator including ray-screening means, a washing device, drying devices, a device for taking up and storing the finished web, and further including a mechanism for effecting the feeding of the web between respective treatment stations and cooperating with a control device for regulating the advance of the web. This known arrangement has been described, for example, in DD Pat. No. 139 073; the ray-screening means described in this patent includes a system of deviation rollers arranged in the range of inlet and outlet openings for the web in the ray-screening walls which facilitate a bound guiding of the web, on the one hand, and cover the inlet and outlet slots to such an extent that the rays cannot leak through the screening walls.
The disadvantage of such known guiding rollers, however, is the fact that the web to be treated in the area of the irradiation device cannot be guided so accurately as is frequently desired. Such an accurate guidance is unconditionally necessary in the case when high-energy irradiation is employed and a uniform effect over the entire length and width of the web is desired. For this purpose, the web must be guided past a ray exit window of the irradiating device in a plane which is exactly parallel to the plane of the window, and such an exact guidance is frequently unattainable by means of prior-art guiding rollers. The exact guidance is particularly difficult to achieve with webs having edges susceptible to curling or rolling-in, as is the case with knitted fabrics, and the like.
In addition, a short-term intensive treatment by radiation causes such changes in the molecular structure of the fibers which results in a change in the size of the web, particularly in an undesired shrinkage both in longitudinal and transverse directions; at the same time, the variation in transverse dimension due to the tension exerted by guiding rollers in longitudinal direction on the web is still increased.
Accordingly, such prior-art guiding rollers are in practice limited to certain applications only and are unsuitable for all kinds of webs to be treated.